The present invention relates to park-brake monitoring-systems of vehicles for monitoring the operational state of the park-brake system of the vehicle and/or monitoring the park-brake system of the vehicle for potential malfunctions. Vehicles to which the present invention relates generally include one or more frame structures to which a majority of other components of the vehicle are engaged directly or indirectly and which serve to locate the other components of the vehicle relative to one another. Additionally vehicles that the present invention relates to generally include a suspension system to which the one or more frame structures of the vehicle are engaged and from which the one or more frame structures derive support. The suspension system of a vehicle to which the present invention relates includes one or more ground-engaging components. As mentioned above, vehicles to which the present invention relates comprise a park-brake system. The function of the park-brake system is to selectively allow or prevent movement of the vehicle along the ground dependent upon the operational state of the park-brake system. One or more of the ground-engaging components of vehicles to which the present invention relates are engaged to the frame structure(s) thereof in such a manner that, when the park-brake system has a released operational state, those ground-engaging components can rotate relative to the frame structure(s) and the ground, thus, providing for easy rolling of the vehicle over the ground. The park-brake system is constructed and engaged to the vehicle in such a manner that, when the park-brake system has a set operational state, the park-brake system is engaged between one or more of the ground-engaging components and the frame structure(s) of the vehicle in such a manner to prevent relative rotation therebetween and to, thus, prevent movement of the vehicle along the ground. Thus, when an operator of the vehicle wishes to drive the vehicle, they effect a released operational state of the park-brake system to allow movement of the vehicle along the ground and, when the operator of the vehicle wishes to leave the vehicle unattended, they can effect a set operational state of the park-brake system to prevent inadvertent, undesirable movement of the vehicle along the ground.
There are many known constructions of vehicles and park-brake systems that function in the manner described above. All such systems generally comprise braking components that are mounted directly or indirectly to the frame structure(s) of the vehicle or the ground-engaging components of the vehicle. When such park-brake systems have a released operational state, the braking components thereof are disengaged from whichever of the frame structure(s) and the ground-engaging components they are not mounted to. In order to effect a set operational state of such a park-brake system the braking components thereof must be moved to a position in which they are engaged to both the frame structure(s) of the vehicle and the ground-engaging components in such a manner preventing relative rotation therebetween. Such park-brake systems include park brake-actuating components that are engaged to the braking components in such a manner that they can be actuated in order to move the braking components from the positions they occupy when the park-brake system has a released operational state to the positions they occupy when the park-brake system has a set operational state. The park-brake-actuating components can further be retracted to allow or effect movement of the braking component(s) from the position(s) they occupy when the park-brake system has a set operational state to the position(s) they occupy when the park-brake system has a released operational state. Such park-brake systems further include park-brake-system controls that are useable by an operator of the vehicle to control actuation and retraction of the park-brake-actuating components and, thus, the operational state of the park-brake system.
Many different park-brake monitoring-systems are known. The purpose of known park-brake monitoring-systems is to either monitor the operational state of the park-brake system or to monitor the park-brake system for potential failure thereof. Known park-brake monitoring-systems include sensor(s) that are communicatively linked to logic device(s), visual indicators, and/or audio indicators. These sensor(s) of known park-brake monitoring-systems produce signals that are dependent upon conditions present in the park-brake system including conditions related to the braking components thereof, the park-brake-actuating components thereof, and/or the park-brake-system controls thereof. The sensor(s) of known park-brake monitoring systems include selected-state sensor(s) and/or actual-state sensor(s). Selected-state sensors interact with the park-brake-system controls and produce signals that are dependent upon conditions dictated by the state of the park-brake-system controls. Thus, the signals produced by selected-state sensors are implicative of the selected operational state of the park-brake system and the operational state (set or released) that the park-brake system has, when the park-brake system is functioning properly. Actual-state sensors interact with the park-brake-actuating components of the park-brake system and produce signals that are dependent upon conditions dictated by the positions of the park-brake-actuating components. Thus, the signals produced by actual-state sensors are implicative of the actual operational state (set or released) of the park-brake system. Many known park-brake monitoring-systems utilize either only selected-state sensor(s) or only actual-state sensor(s). Known park-brake monitoring-systems that have both selected-state sensor(s) and actual-state sensor(s) utilize the signals produced by the selected-state sensor(s) and the signals produced by the actual-state sensor(s) independently. Monitoring of a park-brake system by independently utilizing signals produced by selected-state sensor(s) and actual-state sensor(s) can result in false determinations of the actual operational state of the park-brake system as well as false determinations that the park-brake system is functioning properly and false determinations that the park-brake system is malfunctioning. For example a determination of the operational state of a park-brake system based only upon signals from selected-state sensor(s) may be erroneous if the park-brake-actuating components or the braking components of the park-brake system are malfunctioning. Also a determination of proper functioning or malfunctioning of the park-brake system based only upon signals produced by the actual-state sensor(s) may be erroneous if the park-brake monitoring-system is malfunctioning.
As a result, an object of the present invention is to provide a park-brake monitoring-system that is less likely to produce false indications of the actual operational state of the park-brake system it monitors and/or that is capable of providing accurate indications of malfunction of the park-brake monitoring-system and/or the park-brake system in situations where known park-brake monitoring systems would not provide an indication of such malfunctions.
The park-brake monitoring-system of the present invention includes one or more selected-state sensor(s) and one or more actual-state sensor(s). The park-brake monitoring-system of the present invention also includes one or more logic device(s), one or more of which are communicatively linked with both one or more of the selected-state sensor(s) and one or more of the actual-state sensor(s) of the park-brake monitoring-system. The selected-state sensor(s) of the park-brake monitoring-system interact with the park-brake-system controls of the park-brake system it monitors and produce and communicate to the logic device(s) signals that are implicative of a requested operational state of the park-brake system. The actual-state sensor(s) of the park-brake monitoring-system interact with the park-brake-actuating components of the park-brake system it monitors and produce and communicate to the logic device(s) signals that are implicative of an actual operational state of the park-brake system. The logic device(s) of the park-brake monitoring-system operate according to logic to produce monitoring signals that are dependent upon both the signals received from the selected-state sensor(s) and the actual-state sensor(s). The monitoring signals produced by the logic device(s) of the park-brake monitoring-system include signals indicative of an operational state of the park-brake system it monitors and/or error signals that indicate that the park-brake system and/or the park brake monitoring system is malfunctioning. Because the park-brake monitoring-system of the present invention utilizes signals from both the selected-state sensor(s) and the actual-state sensor(s) in dependent manner the possibility of erroneous monitoring signals being produced by the logic device(s) of the park-brake monitoring system is significantly reduced as compared to prior art park-brake monitoring-systems.
Thus, it can be seen that the above-mentioned object, as well as others not mentioned, have been met by the park-brake monitoring-system of the present invention.